One of two different methods are generally used in a reel-up for winding a continuous web manufactured in a paper machine to a finished reel of paper, depending on the type of reeling drum used in the reel-up. The first method uses an empty reeling drum, also termed a core shaft, for production of coreless paper reels, while in the second alternative a hollow core is applied on said reeling drum in the form of a non-deformable cylindrical sleeve, preferably of cardboard. In this latter case the core usually consists of a tube built up of a multi-layered wall of wound paper which has been laminated with a suitable binder such as water glass. For this category of empty core, intended for paper reels, the diameter may generally reach approximately 40-50 cm.
At the start of reeling, the paper web is secured to the core, usually with the aid of a strip of adhesive or tape. In order to achieve continuous production of paper reels, new reeling drums are constantly supplied with empty cores from some type of store, also known as the core shaft stock. This stock is preferably arranged close to the surface winding drum at the upstream end of the reel-up, and suitably at a level just above the production line of the reel-up in order to save space. The stock must then be continuously replenished as the reeling drums with the cores are used up by the reel-up. This is done by the reeling drums being pulled or pushed out of the cores of the finished paper reels in a feed-back station with the aid of a shearing member in the form of a pull-out means in a shaft-extracting station, and thereafter being inserted into a new empty core in the manner described below. In view of the ungainliness of the paper reel, the shearing member is usually arranged immediately downstream and immediately adjacent the drive side of the reel-handling section of the reel-up, i.e., on the side where the cores are fed in, so they can be returned as the finished reels are taken care of by a transport arrangement provided there, e.g., a sliding carriage or conveyor belt, and removed to the next work station which is generally some type of conversion equipment.
Here the paper cores are also recovered from the paper reels, said cores being placed in an intermediate store consisting of some form of transport container so that they also are re-used, as return cores, in the production of paper reels. From this intermediate store said return cores are then taken manually or using a work vehicle, to a storage arrangement for empty cores where the cores are either emptied from the transport container directly down onto the feed-out ramp, or down into some form of substantially vertical storage container for cores, a core stock, fitted at the upstream side of the feed-out ramp. The storage arrangement for new empty cores is generally located at the end of the production line, in conjunction with said feed-back station and is thus easily accessible to the above-mentioned work vehicle. At the downstream end of the feed-out ramp of the storage arrangement, the empty cores are fed one at a time to a width corresponding to the width of the paper web, to a lifting table arranged between the two stand parts of the reel-up, after which the reeling drum last withdrawn is again introduced into the empty core(s), by the above-mentioned shearing device, and thus forms a reeling drum ready for reeling. The finished reeling drum is then moved to the above-mentioned stock of reels so that the process can start again and thus progress continuously.
In other types of equipment for reeling material webs, primarily for reeling onto short cores with slim dimensions which can be handled in a much simpler manner, it is already known to arrange a special work station where new cores are combined with return cores to form reeling drums. Return cores that have been damaged during the handling process are first repaired in a splicing apparatus belonging to the equipment, where damaged parts of the cores are cut off and the remaining pieces joined together to form new, whole cores.
However, for empty cores intended for the extremely heavy and ungainly paper reels produced in a paper reel-up, such a method does not function well because of the extremely large dimension and weight of the cores. To facilitate handling these cores, which cannot easily be fed manually, a work vehicle or other work tool is required. A major problem is then how this work vehicle can move a large number of return cores without them being damaged.
When filling the magazine or container in the core store, damage such as buckling, torn ends, etc., may be caused to the paper cores, making them unusable. If such a damaged core is not detected the direct consequence may be a relatively expensive stop in production since, in the worst case, the reel-up must be stopped in order to remove the damaged core. To avoid this, each core must be carefully inspected which is a laborious process. The cores may also become clamped in the core stores known hitherto, where the cores lie loose, piled one on top of the other in a complicated jumble, since they fall crookedly and become caught in the container itself or when being transferred to the feed-out ramp through the opening of the container. In all conventional storage arrangements for empty cores where some form of container is used, this must in some way be funnel-shaped to allow the cores to be fed out one by one through the outlet opening of the container, and said container therefore takes up unnecessarily much space in relation to the number of cores stored therein. A rectangular magazine, which could hold many more cores in relation to its height and volume, cannot be used today for the reasons stated above.
Furthermore, with the core containers used hitherto, after moving the transport container filled at the conversion equipment to the storage arrangement for empty cores, the truck driver must manually empty the empty cores from the transport container down onto the feed-out ramp or down into the storage arrangement above said vertical core store. To perform this tedious work, the driver is forced to get down from his truck and then activate the actuator for the container's outlet hatch. Due to the problem described above, of empty cores landing crookedly in the container and thus being clamped, the driver must carefully check the position of the empty cores inside the container after each delivery before activating the actuator for the outlet hatch.
One example of the older technology described above is the conversion equipment shown in Swedish patent specification SE-C-196 384 which, however, is only suitable for a rewinder where the paper reels coming from the reel-up are rewound onto the much slimmer paper cores described in said publication, which are used for rolls of household paper or toilet paper, for instance. The storage arrangement shown in this publication cannot be used for the considerably larger paper cores utilized in drum winders producing paper reels with a diameter and length of several meters, and the cores which cannot be moved in any great quantities manually but must be transported with the aid of a work vehicle.
However, the design shown in this publication clearly illustrates the problems caused by cores lying loose in a funnel-shaped magazine. Such a construction must include a vibrator to prevent pile-ups of the cores and having to use a funnel-shaped container instead of a rectangular one results in a large amount of un-utilized space inside the container.
Another example of old technology is the conversion equipment described in the U.S. patent specification U.S. Pat. No. 4,716,646 where smaller reeling drums are fitted together and placed resting directly on top of each other in a stack in an intermediate store constituting a small container on wheels from which the finished reeling drums are withdrawn in a manner not described, probably manually.
The object of the present invention is to provide an improved and simplified storage arrangement for empty cores for use in a reel-up in a paper machine in which paper is wound onto said empty cores to form paper reels, in which filling and feeding out the empty cores from the storage arrangement is greatly improved.
Another object of the invention is to provide a storage arrangement which is self-emptying.
A third object of the invention is to provide a storage arrangement having a magazine that ensures feed-out of the empty cores without risk of their being damaged, being clamped or jamming during said feed-out in the magazine itself or during transfer to the feed-out ramp.
Another object of the invention is to provide a storage arrangement allowing a better ratio between the volume and height of the container and the maximum number of empty cores stored therein.
Yet another object of the invention is to provide a storage arrangement having an empty core magazine that allows the contents to be inspected and checked from the outside.
Finally, it is also an object of the invention to provide a storage arrangement having a magazine which can easily be transported from the filling station to the storage arrangement for empty cores with the aid of a truck and in a manner facilitating vision of the driver during transport.